<?php // $Id: autogroup.php,v 1.1.2.4 2007/11/19 22:53:50 skodak Exp $
/**
 * Create and allocate users go groups
 *
 * @author  Matt Clarkson mattc@catalyst.net.nz
 * @version 0.0.1
 * @license http://www.gnu.org/copyleft/gpl.html GNU Public License
 * @package groups
 */

require_once('../config.php');
require_once('lib.php');
require_once('autogroup_form.php');

if (!defined('AUTOGROUP_MIN_RATIO')) {
	define('AUTOGROUP_MIN_RATIO', 0.7); // means minimum member count is 70% in the smallest group
}

$courseid = required_param('courseid', PARAM_INT);

if (!$course = get_record('course', 'id', $courseid)) {
	error('invalidcourse');
}

// Make sure that the user has permissions to manage groups.
require_login($course);

$context	   = get_context_instance(CONTEXT_COURSE, $courseid);
$systemcontext = get_context_instance(CONTEXT_SYSTEM);
require_capability('moodle/course:managegroups', $context);

$returnurl = $CFG->wwwroot.'/group/index.php?id='.$course->id;

$strgroups		   = get_string('groups');
$strparticipants	 = get_string('participants');
$strautocreategroups = get_string('autocreategroups', 'group');

// Print the page and form
$navlinks = array(array('name'=>$strparticipants, 'link'=>$CFG->wwwroot.'/user/index.php?id='.$courseid, 'type'=>'misc'),
				  array('name' => $strgroups, 'link' => "$CFG->wwwroot/group/index.php?id=$courseid", 'type' => 'misc'),
				  array('name' => $strautocreategroups, 'link' => null, 'type' => 'misc'));
$navigation = build_navigation($navlinks);

$preview = '';
$error = '';

/// Get applicable roles
$rolenames = array();
if ($roles = get_roles_used_in_context($context, true)) {
	$canviewroles	= get_roles_with_capability('moodle/course:view', CAP_ALLOW, $context);
	$doanythingroles = get_roles_with_capability('moodle/site:doanything', CAP_ALLOW, $systemcontext);

	foreach ($roles as $role) {
		if (!isset($canviewroles[$role->id])) {   // Avoid this role (eg course creator)
			continue;
		}
		if (isset($doanythingroles[$role->id])) {   // Avoid this role (ie admin)
			continue;
		}
		$rolenames[$role->id] = strip_tags(role_get_name($role, $context));   // Used in menus etc later on
	}
}

/// Create the form
$editform = new autogroup_form(null, array('roles' => $rolenames));
$editform->set_data(array('courseid' => $courseid, 'seed' => time()));

/// Handle form submission
if ($editform->is_cancelled()) {
	redirect($returnurl);

} elseif ($data = $editform->get_data(false)) {

	/// Allocate members from the selected role to groups
	switch ($data->allocateby) {
		case 'no':
		case 'random':
		case 'lastname':
			$orderby = 'lastname, firstname'; break;
		case 'firstname':
			$orderby = 'firstname, lastname'; break;
		case 'idnumber':
			$orderby = 'idnumber'; break;
		default:
			error('Unknown ordering');
	}
	$users = groups_get_potential_members($data->courseid, $data->roleid, $orderby);
	$usercnt = count($users);

	if ($data->allocateby == 'random') {
		srand($data->seed);
		shuffle($users);
	}

	$groups = array();

	// Plan the allocation
	if ($data->groupby == 'groups') {
		$numgrps	= $data->number;
		$userpergrp = floor($usercnt/$numgrps);

	} else { // members
		$numgrps	= ceil($usercnt/$data->number);
		$userpergrp = $data->number;

		if (!empty($data->nosmallgroups) and $usercnt % $data->number != 0) {
			// If there would be one group with a small number of member reduce the number of groups
			$missing = $userpergrp * $numgrps - $usercnt;
			if ($missing > $userpergrp * (1-AUTOGROUP_MIN_RATIO)) {
				// spread the users from the last small group
				$numgrps--;
				$userpergrp = floor($usercnt/$numgrps);
			}
		}
	}

	// allocate the users - all groups equal count first
	for ($i=0; $i<$numgrps; $i++) {
		$groups[$i] = array();
		$groups[$i]['name']	= groups_parse_name(trim($data->namingscheme), $i);
		$groups[$i]['members'] = array();
		if ($data->allocateby == 'no') {
			continue; // do not allocate users
		}
		for ($j=0; $j<$userpergrp; $j++) {
			if (empty($users)) {
				break 2;
			}
			$user = array_shift($users);
			$groups[$i]['members'][$user->id] = $user;
		}
	}
	// now distribute the rest
	if ($data->allocateby != 'no') {
		for ($i=0; $i<$numgrps; $i++) {
			if (empty($users)) {
				break 1;
			}
			$user = array_shift($users);
			$groups[$i]['members'][$user->id] = $user;
		}
	}

	if (isset($data->preview)) {
		$table = new object();
		if ($data->allocateby == 'no') {
			$table->head  = array(get_string('groupscount', 'group', $numgrps));
			$table->size  = array('100%');
			$table->align = array('left');
			$table->width = '40%';
		} else {
			$table->head  = array(get_string('groupscount', 'group', $numgrps), get_string('groupmembers', 'group'), get_string('usercounttotal', 'group', $usercnt));
			$table->size  = array('20%', '70%', '10%');
			$table->align = array('left', 'left', 'center');
			$table->width = '90%';
		}
		$table->data  = array();

		foreach ($groups as $group) {
			$line = array();
			if (groups_get_group_by_name($courseid, $group['name'])) {
				$line[] = '<span class="notifyproblem">'.get_string('groupnameexists', 'group', $group['name']).'</span>';
				$error = get_string('groupnameexists', 'group', $group['name']);
			} else {
				$line[] = $group['name'];
			}
			if ($data->allocateby != 'no') {
				$unames = array();
				foreach ($group['members'] as $user) {
					$unames[] = fullname($user, true);
				}
				$line[] = implode(', ', $unames);
				$line[] = count($group['members']);
			}
			$table->data[] = $line;
		}

		$preview .= print_table($table, true);

	} else {
		$grouping = null;
		$createdgrouping = null;
		$createdgroups = array();
		$failed = false;

		// prepare grouping
		if (!empty($data->grouping)) {
			$groupingname = trim($data->groupingname);
			if ($data->grouping < 0) {
				$grouping = new object();
				$grouping->courseid = $COURSE->id;
				$grouping->name	 = $groupingname;
				if (!$grouping->id = groups_create_grouping(addslashes_recursive($grouping))) {
					$error = 'Can not create grouping'; //should not happen
					$failed = true;
				}
				$createdgrouping = $grouping->id;
			} else {
				$grouping = groups_get_grouping($data->grouping);
			}
		}

		// Save the groups data
		foreach ($groups as $key=>$group) {
			if (groups_get_group_by_name($courseid, $group['name'])) {
				$error = get_string('groupnameexists', 'group', $group['name']);
				$failed = true;
				break;
			}
			$newgroup = new object();
			$newgroup->courseid = $data->courseid;
			$newgroup->name	 = $group['name'];
			if (!$groupid = groups_create_group(addslashes_recursive($newgroup))) {
				$error = 'Can not create group!'; // should not happen
				$failed = true;
				break;
			}
			$createdgroups[] = $groupid;
			foreach($group['members'] as $user) {
				groups_add_member($groupid, $user->id);
			}
			if ($grouping) {
				groups_assign_grouping($grouping->id, $groupid);
			}
		}

		if ($failed) {
			foreach ($createdgroups as $groupid) {
				groups_delete_group($groupid);
			}
			if ($createdgrouping) {
				groups_delete_grouping($createdgrouping);
			}
		} else {
			redirect($returnurl);
		}
	}
}

/// Print header
print_header_simple($strgroups, ': '.$strgroups, $navigation, '', '', true, '', navmenu($course));
print_heading($strautocreategroups);

if ($error != '') {
	notify($error);
}

/// Display the form
$editform->display();

if($preview !== '') {
	print_heading(get_string('groupspreview', 'group'));

	echo $preview;
}

print_footer($course);
?>